Effect of tungsten absorption edge filter on diagnostic x-ray spectra, image quality and absorbed dose to the patient

Yamaguchi, Chiri; Yamamoto, Teruo; Terada, Hiromi; Akisada, Masayoshi

doi:10.1088/0031-9155/28/3/003

Cited by 15 publications

(4 citation statements)

References 10 publications

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“…In previous studies using W filters, which increased the overall image quality, the entrance dose decreased from 22% to 15%, and the overall image quality was more uniform [ 17 ]. Other studies have also reported that the addition of a 0.1mm W filter reduced the total absorbed dose by 0.73 times and did not reduce the overall image quality [ 15 ]. Additionally, a study has reported that the W filter, which is the bandwidth filter, reduced the radiation exposure of patients by >50% compared to the Al filter without decreasing the image quality [ 5 , 38 , 39 ].…”

Section: Discussionmentioning

confidence: 99%

“…The radiation dose and image quality should be optimized to balance the patient dose with the radiographic image quality, which is determined by tube voltage and additional filtration [ 5 , 11 , 12 , 13 ]. Although not all photons contribute to image formation, most low-energy photons, which are absorbed by the patient and do not contribute to the formation of images, have been studied for selective removal of high-energy photons [ 14 , 15 ].…”

Section: Introductionmentioning

confidence: 99%

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Dose Reduction and Image Quality Optimization of Pediatric Chest Radiography Using a Tungsten Filter

et al. 2022

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The use of diagnostic radiology in pediatric patients has increased, and various positive effects have been reported, including methods to reduce radiation doses in children. Research has been conducted to preserve image quality while reducing exposure and doses in pediatric patients. This study aimed to measure four different filters to identify an optimized filter for pediatric patients. The experiment was conducted using four types of filters, including aluminum, copper, molybdenum, and tungsten. The optimal filter thickness was verified using a histogram to visually evaluate the spectrum by filter thickness, effective dose on a pediatric phantom, entrance skin dose, organ absorbed dose using the PC-based Monte Carlo (PCXMC) program version 2.0 simulation, figure of merit (FOM), and image quality. As a result of measuring the spectrum according to the tube voltage and the four types of filters, dose reduction and contrast improvement effects were obtained with a 0.05 mm tungsten filter. Additionally, effective entrance skin and organ absorbed dose decreased with the said filter. The aluminum, copper, and molybdenum filters demonstrated that the effective dose scarcely decreased even when the thickness was increased; meanwhile, the effective dose decreased when the tungsten filter was 0.05 mm. The FOM with a 0.05 mm tungsten increased by 91% in the lung field and 39% in the mediastinal field. The entrance skin and organ absorbed dose in pediatric patients can be reduced by removing low-energy photons that fail in image formation using a tungsten filter.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Dose Reduction and Image Quality Optimization of Pediatric Chest Radiography Using a Tungsten Filter

et al. 2022

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“…A high intensity scanning point source (for longitudinal scan at each rotational step) or a stationary line source can be used. Our choice is to use an x-ray tube to provide filtered x-rays or characteristic x-rays when a heavy-element is irradiated [39], [40]. In both cases, the transmission flux is reduced in intensity and centers on a narrow energy band suitable for photon counting detection.…”

Section: C-spect-imentioning

confidence: 99%

C-SPECT—A Clinical Cardiac SPECT/Tct Platform: Design Concepts and Performance Potential

Chang

Ordoñez

Liang

et al. 2009

IEEE Trans. Nucl. Sci.

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Because of scarcity of photons emitted from the heart, clinical cardiac SPECT imaging is mainly limited by photon statistics. The sub-optimal detection efficiency of current SPECT systems not only limits the quality of clinical cardiac SPECT imaging but also makes more advanced potential applications difficult to be realized. We propose a high-performance system platform - C-SPECT, which has its sampling geometry optimized for detection of emitted photons in quality and quantity. The C-SPECT has a stationary C-shaped gantry that surrounds the left-front side of a patient’s thorax. The stationary C-shaped collimator and detector systems in the gantry provide effective and efficient detection and sampling of photon emission. For cardiac imaging, the C-SPECT platform could achieve 2 to 4 times the system geometric efficiency of conventional SPECT systems at the same sampling resolution. This platform also includes an integrated transmission CT for attenuation correction. The ability of C-SPECT systems to perform sequential high-quality emission and transmission imaging could bring cost-effective high-performance to clinical imaging. In addition, a C-SPECT system could provide high detection efficiency to accommodate fast acquisition rate for gated and dynamic cardiac imaging. This paper describes the design concepts and performance potential of C-SPECT, and illustrates how these concepts can be implemented in a basic system.

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“…Historically, dose reduction through the use of filters has involved compromises among different types and thicknesses of filter materials, the effects on image quality from changes in the x-ray beam spectra, and considerations of additional tube loading which impact tube life, focal spot size, and exposure times. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] Regulatory and advisory agencies have responded by issuing requirements or guidelines setting forth minimum filtration standards. [17][18][19][20] Although the skin entrance dose decreases fairly rapidly with increasing filtration ͑with the kVp and exit dose held constant͒ this is generally not the case for most organs.…”

Section: Introductionmentioning

confidence: 99%

Effective dose in diagnostic radiology as a function of x-ray beam filtration for a constant exit dose and constant film density

Behrman

Yasuda

1998

Med. Phys.

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Individual organ absorbed dose and total effective dose for nine common radiographic projections were investigated as a function of half-value-layer, HVL, and total equivalent filtration for the following cases: (1) with the patient exit dose held constant and (2) with the film density held constant. As expected, the absorbed dose to organs proximal to the x-ray beam entry point tracked with skin dose as a function of HVL, whereas organ dose distal to the x-ray beam entry point was almost independent of HVL. Dose to organs near mid-line showed an intermediate HVL dependence. For the nine radiographic projections, increasing the total filtration from 1.5 to 4.0 mm Al while holding the kVp fixed resulted in mean decreases in the effective dose of 17% for the case of a constant exit dose, and 25% for a constant film density with a "400 speed" rare-earth screen-film system. The decreases in the mean skin entrance doses were 38% and 45%, respectively. With the screen-film system, the average effective dose decreased at 16% per mm of added Al between 1.5 and 2.5 mm Al total filtration, and at 7% per mm between 2.5 and 4.0 mm. These results partially support the NCRP Report No. 102 recommendation that the minimum filtration be 2.5 mm Al for general diagnostic x-ray tubes. They also suggest, using the linear no-threshold radiation risk model, that further significant reductions in stochastic risk to the U.S. population can be achieved by raising the minimum beyond 2.5 mm. Experience over a 12 year period in our tertiary care teaching hospital indicates that adding 1-1.5 mm Al filtration beyond the 2.5 mm minimum does not pose a problem in terms of additional tube loading or reduction in image quality. However, these issues need to be more formally addressed.

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Effect of tungsten absorption edge filter on diagnostic x-ray spectra, image quality and absorbed dose to the patient

Cited by 15 publications

References 10 publications

Dose Reduction and Image Quality Optimization of Pediatric Chest Radiography Using a Tungsten Filter

Dose Reduction and Image Quality Optimization of Pediatric Chest Radiography Using a Tungsten Filter

C-SPECT—A Clinical Cardiac SPECT/Tct Platform: Design Concepts and Performance Potential

Effective dose in diagnostic radiology as a function of x-ray beam filtration for a constant exit dose and constant film density

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